It’s not a one shot lenses but several shots stitched together. I use a Nikkor 10.5mm fish-eye on a D200. For the stitching I use PTGui and after that Photoshop to correct the errors, improve the overall image quality, etc.

You can find a lot of good information here

how do you do your Panoramas?
for me it looks like a one click panorama image!

what lenses and programs do you use?

Thanks